The goal of Project 1 is to investigate the role of the cholesteryl ester transfer protein (CETP) in lipoprotein metabolism and atherogenesis and the regulation of CETP gene expression. The experimental approach will place major emphasis on the use of transgenic and knock-out mice. The project is directly related to the major theme of the program project i.e. the investigation of lipid and lipoprotein metabolism and atherogenesis using cell culture models and genetically manipulated mice. The specific aims are 1) to test the hypothesis that CETP expression increases the atherogenicity of the plasma lipoproteins, by breading the CETP transgene into mice with apoE or LDL receptor genes knocked out; in subsequent studies the effects of hypertriglyceridemia in these models will be examined by making further crosses with other mutant mouse strains; 2) to determine the consequences of CETP expression in adipose tissue and to assess possible in vivo CETP-LPL interactions in m ice with adipose- specific expression of CETP and /or LPL; 3) to define cis- and trans- acting factors mediating sterol regulation and tissue-specific expression of the CETP gene in transgenic mice and in cell culture; and 4) to investigate the function and regulation of alternative splicing of the CETP gene by characterizing transgenic mice expressing an inducible metallothionein-CETP transgene with exon 9 sequences omitted or a natural flanking region CETP transgene with the option to splice out exon 9. These studies will involve extensive interactions without he Transgenesis Core and with Projects 2 (Breslow, LPL), 4 (Jiang, phospholipid transfer protein) and 5 (Smith, apoE). This project will provide new information on the regulation of HDL and VLDL metabolism and on the relationship of HDL to atherogenesis. If CETP has pro-atherogenic activities as suspected, a detailed understanding of the regulation of CETP gene expression may provide a key to decreasing CETP levels as a means of increasing HDL levels and preventing atherosclerosis in humans.